1. Field of the Invention
The present invention relates to an electrical connector for electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), and particularly to an electrical connector with a cover configured to minimize any distortion thereof.
2. Description of Prior Art
CPU sockets are widely used in personal computer (PC) systems to electrically connect CPUs with PCBs. A typical CPU socket comprises a base, and a cover slidably engaged on the base. The cover drives pins of the CPU into electrical engagement with electrical contacts received in the base.
A conventional CPU socket with a slidable cover is disclosed in xe2x80x9cDevelopment of a ZIF BGA Socketxe2x80x9d (May 2000, P16xcx9c18, Connector Specifier Magazine). Similar structures are also disclosed in U.S. Pat. Nos. 4,988,310, 6,375,485, 6,315,592, 6,250,941, and 6,186,815.
Referring to FIGS. 7 and 8, a cover of a conventional CPU socket comprises a main plate 51, and two side plates 53 depending from opposite sides of the main plate 51 respectively. A multiplicity of holes 52 is defined through the main plate 51. The holes 52 are arranged in a rectangular array. Each hole 52 comprises a guiding opening 521 at a top surface 511 of the main plate 51, to facilitate insertion of a corresponding pin of the CPU into the hole 52. Each hole 52 further comprises a receiving portion 522 at a bottom surface 512 of the main plate 51, for receiving the corresponding pin of the CPU. The receiving portion 522 is below and in communication with the guiding opening 521.
As a result of the configurations of the guiding openings 521 and the receiving portions 522, a span of the main plate 51 between adjacent holes 52 varies from the top surface 511 to the bottom surface 512.
During soldering of the CPU socket to the PCB, the CPU socket is heated to establish electrical connection with the PCB. The main plate 51 expands. Because the said span of the main plate 51 varies, the main plate 51 transversely expands in a non-uniform manner. Thus the top surface 511 and the bottom surface 512 are prone to distort. The cover is prone to warp and distort relative to a base of the CPU socket during such soldering.
When the cover is not parallel to the base, this can adversely affect the reliability of electrical transmission through the CPU socket. It can even result in failure of electrical connection between the CPU socket and the CPU, due to faulty insertion of the pins of the CPU into the CPU socket.
A new electrical connector that overcomes the above-mentioned disadvantages is desired.
Accordingly, an object of the present invention is to provide an electrical connector for electrically connecting an electronic package such as a CPU with a circuit substrate such as a PCB, the electrical connector having a distortion-resistant cover configured to minimize any distortion thereof during installation, use or operation of the electrical connector.
To achieve the above-mentioned object, an electrical connector for electrically connecting a CPU with a PCB is provided by the present invention. In a preferred embodiment, the electrical connector comprises an insulative body, and a multiplicity of conductive terminals received in the body. The body comprises a base fixed to the PCB, and a cover slidably mounted on the base.
The cover comprises a main plate, and two side plates depending from opposite sides of the main plate respectively. A multiplicity of through holes is defined in the main plate. The through holes are arranged in a rectangular array. Each through hole comprises a funneled guiding opening at a top surface of the main plate, and a cylindrical receiving portion at a bottom surface of the main plate. The receiving portion is below and in communication with the guiding opening. A multiplicity of recesses is defined in the bottom surface of the main plate, respectively between a multiplicity of adjacent through holes.
Accordingly, a span of the main plate between adjacent through holes is substantially the same from the top surface to the bottom surface. Any transverse expansion or contraction of the main plate during installation, use or operation of the electrical, connector is substantially uniform.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: